The case of the failing ant copy filterset

I wanted to set a couple of Windows environment variables from Ant. The environment key-value pairs are stored on the HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerEnvironment key in the registry. As a starting point I used the registry editor to export all keys. I called the file environment.reg.template and modified it to look something like this:

I ran the ant script and looked in environment.reg. It still looked just like environment.reg.template! Running again obviously didn’t work, but I had to try! 🙂 When did a cut & paste of the above and sent to a colleague he could not reproduce the issue. I thought hard about it and then it dawned on me: the registry editor exported a file in Unicode format. I used notepad to convert it to ANSI and then everything worked fine. Case closed.